Supporting information for
Comparison and analysis of zinc and cobalt-based systems as catalytic entities
for the hydration of carbon dioxide.
Edmond Y. Lau, Sergio E. Wong, Sarah E. Baker, Jane P. Bearinger, Lukasz Koziol,
Carlos A. Valdez, Joseph H. Satcher Jr, Roger D. Aines* and Felice C. Lightstone*
Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory,
Livermore, California, United States of America
Corresponding authors aines1@llnl.gov and felice@llnl.gov
Text S1
Materials. All reagents used were of analytical grade, were purchased from commercial
suppliers and were used as received. o-Phenylenediamine was purchased from Alfa Aesar (Ward
Hill, MA). 1H NMR (600 MHz) and 13C NMR (150 MHz) spectra were recorded in D2O unless
otherwise specified with a Bruker Avance AVB-600 nuclear magnetic resonance (NMR)
spectrometer equipped with a 5 mm z-gradient broadband probe. Data are presented as follows:
chemical shift (parts per million, ppm), multiplicity s = singlet, d = doublet, m = multiplet, br =
broad, coupling constant, J (in hertz). Elemental analyses were obtained at the LLNL
Microanalytical Facility.
Zinc complex of Tris(6-sulfobenzimidazolylmethyl)amine [sulfonated-Ben]. The sodium salt
of tris(6-sulfobenzimidazolylmethyl)amine (300 mg, 0.42 mmol) was dissolved in deionized
water (5 mL) in a 25 mL round bottom flask. The light grey solution was warmed to 50 oC and
treated with zinc(II) perchlorate hexahydrate (208 mg, 0.56 mmol) in deionized water (1 mL).
The resulting solution was stirred at 50 oC for 2 h and then at ambient temperature for 1 h. The
flask was evaporated and the light grey solid was dried under vacuum at ambient temperature
overnight to obtain the zinc(II) containing complex (397 mg, 95%). 1H NMR data matched the
one previously published [1] while the 13C NMR contained multiple peaks due to the presence of
all the possible isomeric complexes. Anal. (C24H22Cl2N7Na3O19S3Zn•2H2O) C, 28.43; H, 2.19;
N, 6.99; Found: C, 28.92; H, 2.42; N, 7.02.
Stopped-Flow Measurements
Experimental catalytic rate constants for the CO2 hydration reaction catalyzed by tris(6sulfobenzimidazolylmethyl)amine-Zn(II) were determined using stopped-flow
spectrophotometry using methods similar to those previously described [2].
1. Nakata, K.; Shimomura, N.; Shiina, N.; Izumi, M.; Ichikawa, K.; Shiro, M. “Kinetic study of
catalytic CO2 hydration by water-soluble model compound of carbonic anhydrase and anion
inhibition effect on CO2 hydration.” J. Inorg. Biochem. 2002, 89, 255-266.
2. Koziol, L., Valdez, C. A., Baker, S.E., Lau, E. Y., Floyd, III, W. C., Wong, S. E., Satcher, Jr.,
J. H., Lightstone, F. C., Aines, R. D. “Toward a small molecule, biomimetic carbonic anhydrase
model: theoretical and experimental investigations of a panel of zinc(II) aza-macrocyclic
catalysts.” Inorg. Chem., 2012, 51, 6803-6812.